X should work. However, you can also rebind the key in question: In game, hit escape to open the menu, choose the "options" tab (the one with a picture of a controller on it), scroll down near the bottom. The second to last area is the "Controls" section, look for the "Check / Do Action" listing, it'll show what it currently is, and you can click "set" to change it to whatever you want it to be. Hope that helps!